Baldness (adj.) The loss of hair on the aged male head, signifying advanced age and corresponding wisdom, specifically to younger males. Premature balding is a mimicry by younger, smarter males of their older peers for the sake of gaining political power earlier.
It is a curious thing about people, how they pay so much attention to the "what" of their appearance, but rarely if ever ask the "why". If one is not ignorant, one understands that appearances are based on genetics, and genes always answer a "why", if one can uncover it. There are no accidents in evolution, only the careful hand of natural and sexual selection. So the detection and uncovering of interesting "why"s can be great fun to the curious mind. Hair is interesting stuff, a very human thing, yet barely understood. Baldness, the basis for a large industry in useless products and techniques, has a "why", as explained above. As to why men fight baldness, the answer lies in game theory. An older male either goes for female company on the basis of looks, or on the basis of power. Power lies in the networks of other males he controls, and control comes from wisdom and to some degree, the respect that age brings. The "mid-life crisis" is, for many men, the realization that they need to start relying on their wits instead of their youthful charm. Clearly, men who feel insecure about their strength of mind will hope to avert the onset of age, while confident, strong men will embrace age and the cosmetic changes it brings.